The present invention relates to air fluidized support surfaces for beds. More particularly, the present invention relates to an improved coverlet for an air fluidized bed.
Air fluidized beds have been used as patient support systems in homes, hospitals and nursing homes. Air fluidized beds provide an excellent support surface for patients who are at risk of bed sores because they provide relatively uniform distribution of forces on the body. In addition, fluidized beds are well suited for treatment of patients with skin grafts because the fluidized support surfaces do not produce high shear, frictional forces when the patient moves on the bed. In this type of bed, a fluidizable medium such as tiny spheres formed of glass, ceramics, or silicone is contained within a suitable support and fluidized by air passing through the support. In one design, the fluidizable medium is supported by a diffuser board assembly which is permeable to air but impermeable to the fluidizable medium. A retaining mechanism which is impermeable to air is positioned around the outer edges of the diffuser board assembly to contain the fluidizable medium. An air permeable top sheet encloses the fluidizable medium. Typically, the whole assembly is enclosed in a conventional air permeable mattress pad or coverlet. Air flowing upwardly through the fluidizable medium passes through the top sheet and the coverlet, and then escapes to atmosphere. Examples of this type of air fluidized bed are disclosed in U.S. Pat. Nos. 4,481,686, 4,483,029 and 5,623,736 and U.S. patent application, Ser. No. 08/993,183 now U.S. Pat. No. 6,073,289, all of which are incorporated herein by reference. An example of such beds on the market are Clinitron line of air fluidized therapy units available from Hill-Rom, Inc. (Clinitron is a registered trademark of Hill-Rom, Inc., Batesville, Ind.)
A problem associated with such air fluidized beds is that patient fluids have a tendency to seep through the air permeable coverlet and the top sheet into the tiny beads and the underlying supporting structure. Therefore, the entire bed has to be cleaned and disinfected between successive patients to reduce the risk of cross contamination due to patient fluids. The present invention provides an improved coverlet which is impervious to fluids while allowing the air to escape through a plurality of openings in the side panels of the coverlet. The coverlet can be easily washed and disinfected, avoiding the need for cleaning and disinfecting the entire bed.
According to an illustrated embodiment of the present invention, the coverlet is air and moisture vapor permeable to allow the moisture vapor to escape therethrough. Illustratively, the coverlet material is a fabric coated with a microporous membrane. In another embodiment of the present invention, the coverlet is air and moisture vapor impermeable as well as being fluid impermeable.
Additional features of the present invention will become apparent to those skilled in the art upon consideration of the following detailed description of the illustrated embodiment exemplifying the best mode of carrying out the invention as presently perceived.